Mailing AddressThe University of Texas at AustinInstitute for Cellular and Molecular BiologyOne University Station, A-4800Austin ,TX 78712-0159

Research Summary

We study genetic and epigenetic mechanisms for gene expression changes in polyploids. Polyploidy, or whole-genome duplication (WGD), is an evolutionary innovation for all eukaryotes including some animals and many plants. The common occurrence of polyploidy suggests an evolutionary advantage of having multiple sets of genetic material for adaptive evolution. However, increased gene and genome dosages in autopolyploids (duplication of a single genome) and allopolyploids (combination of two or more divergent genomes) often cause genomic instabilities, chromosomal imbalances, regulatory incompatibilities, and reproductive failures. Aneuploid and polyploid cells in animals and humans are often associated with carcinogenesis. Therefore, new polyploids must establish a compatible relationship between alien cytoplasm and nuclei and among divergent genomes, leading to rapid changes in genome structure, gene expression, and developmental traits such as fertility, inbreeding, apomixis, flowering time, and hybrid vigor. The underlying mechanisms for these changes are poorly understood. We employ genetic and biochemical approaches in combination with DNA microarrays, deep-sequencing, and bioinformatic tools to investigate how changes in DNA sequences, cis- and trans-acting factors, chromatin modifications, RNA-mediated pathways, and regulatory networks modulate silencing and activation of homoeologous genes, giving rise to phenotypic variation in polyploid plants and agricultural crops, many of which have increased biomass and enhanced traits. Elucidating mechanisms for polyploidy may ultimately reveal new approaches to reactivate or silence endogenous genes and lead the way to improve future applications of biotechnology in agriculture and medicine.